ACU 002020.09 (ACU 2020.09 ) – SFA Signal Disruption

ACU 002020.09 (ACU 2020.09)

Code: 002020.09

Shortcode: 2020.09


Error code ACU 2020.09 occurs when the armrest control unit does not receive the required messages from the Steering and Suspension Control Unit (SFA). This communication gap can affect critical steering and suspension functions.


In response to the absence of SFA communications, the control unit imposes a safety restriction, limiting the vehicle’s maximum speed to 30 km/h. This limitation helps ensure safety under compromised system functionality.


  • Verify the integrity of all connections between the armrest control unit and the SFA to ensure they are secure and functioning properly. Look for any potential damages or disconnections.
  • Perform a diagnostic check to identify if there are any secondary errors or issues within the SFA that could be causing the communication failure.
  • Reset both the armrest control unit and the SFA to re-establish default communication protocols and clear any temporary glitches.
  • If the problem persists, the system may require recalibration or firmware updates which should be conducted under the guidance of a John Deere technician.
  • In cases where communication cannot be restored through these steps, it may be necessary to replace faulty hardware components.


Operating the vehicle with limited speed control is a temporary measure and should not substitute for resolving the underlying issue. Regular maintenance and checks of the communication systems can prevent such failures and ensure operational efficiency.